Flat Roofing Systems Overview
Flat roofing systems come in many different types, colors, and thicknesses. But what is the difference between them? The 5 most common types of roof systems are below. Click on the tabs to get more information on each system.
TPO (Thermoplastic PolyOlefin)
| Years Used as Roofing Product | Over 30 Years |
| Base Product | Polyolefins (Polypropylene,Polyethylene) / Plastics |
| Color | White, Gray, Tan + Pallet of colors over 100,000 Square Feet |
| Temperature Impact on Roof | Cools Roof |
| Seaming technology | Heat Welded |
| Thicknesses | .045 to .080 |
| Reinforced | Always Reinforced |
| Puncture Resistance | Good to excellent, depending on thickness |
| Chemical Resistance | Good |
| Environmental Impact | Excellent |
| Slippery With Moisture | Yes |
| Known Problems | Effective welding requires experience. |
EPDM “Rubber” (Ethylene Propylene Diene Monomer)
| Years Used as Roofing Product | Over 50 Years |
| Base Product | Synthetic Rubber |
| Color | Black, White (At price premium) |
| Temperature Impact on Roof | Heats roof (Unless white) |
| Seaming technology | Since 1980, 3” or 6” Seam Tape. Before 1980, liquid adhesives |
| Thicknesses | .045 to .090 |
| Reinforced | Reinforced or Non-Reinforced |
| Puncture Resistance | Good to excellent, depending on thickness |
| Chemical Resistance | Poor |
| Environmental Impact | Moderate |
| Slippery With Moisture | Yes – Moderate |
| Known Problems |
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PVC “Vinyl” (Polyvinyl Chloride)
| Years Used as Roofing Product | Over 50 Years, but formula has changed dramatically over time |
| Base Product | Vinyl / Plastics |
| Color | White, Gray, Tan |
| Temperature Impact on Roof | Cools Roof |
| Seaming technology | Heat Welded, with earlier systems using solvent welded seams |
| Thicknesses | .036 to .090 |
| Reinforced | Always Reinforced (Older non-reinforced systems could shatter) |
| Puncture Resistance | OK to Good, depending on thickness and manufacturer |
| Chemical Resistance | Excellent |
| Environmental Impact | Poor – is actually banned in some countries |
| Slippery With Moisture | Yes -Very |
| Known Problems |
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Modified Bitumen (Mod-Bit)
| Years Used as Roofing Product | Over 50 Years |
| Base Product | Asphalt with modifiers (APP and SBS) |
| Color | Wide variety of colors readily available |
| Temperature Impact on Roof | Dependent on color used |
| Seaming technology | Depends on Installation Method. Typically adhered with hot asphalt or cold adhesives. |
| Thicknesses | 2-5 plys |
| Reinforced | N/A |
| Puncture Resistance | Outstanding |
| Chemical Resistance | Good |
| Environmental Impact | Moderate |
| Slippery With Moisture | No |
| Known Problems |
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Built Up Roof (BUR)
| Years Used as Roofing Product | Over 150 Years |
| Base Product | Asphalt or Coal Tar Pitch |
| Color | Black, Often Graveled |
| Temperature Impact on Roof | Heats Roof |
| Seaming technology | Mopped down with hot asphalt |
| Thicknesses | 2-5 plys |
| Reinforced | N/A |
| Puncture Resistance | Outstanding |
| Chemical Resistance | Good |
| Environmental Impact | Moderate |
| Slippery With Moisture | No |
| Known Problems |
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